Magnetic record body driving mechanism



Feb. 12, 1952 Filed Nov. 9, 1950 E. BARANY ET AL MAGNETIC RECORD BODYDRIVING MECHANISM 5 Sheets-Sheet l Edmund Bcxrcmg Me\v'm Suckter INVENRSFeb. 12, 1952 E. BARANY ETAL MAGNETIC RECORD BODY DRIVING MECHANISM 5Sheets-Sheet 2 Filed Nov. 9, 1950 u n a r .a B d n u m d E Me|vinSacKter- INVENTORS ATTORNEYS Feb. 12, 1952 I BARAN'Y ETAL 2,585,724

MAGNETIC RECORD BODY DRIVING MECHANISM Filed Nov. 9, 1950 s Sheets-Sheets Edmund Bar-am; Melvin SacKter AT TORN EYS Feb. 12, 1952 E. BARANY ETAL2,585,724

MAGNETIC RECORD BODY DRIVING MECHANISM Filed Nov. 9, 1950 5 Sheets-Sheet4 Edmund Bamng Melvin SdcKt -r" AT TORN EYS Feb. 12, 1952 E, BARAN Em2,585,724

MAGNE TIC RECORD BODY DRIVING MECHANISM Filed NOV. 9, 1950 5Sheets-sheet 5 I v I. 13 2 ,5 I I |I ll 35 "H [4 A -m. i

I l 5 -.3D I| I 17 19 39 I 1' I A '|4 Edmund Bd-Pcmg Meivin SacKterINVENTORS OFF ATTORNEYS Patented Feb. 12, 1952 Edmund Barany, Chicago,and Melvin Sackten, Arlington Heights, 111., assignors ...to Amprocorporation, Chicago,

Illinois 111. a corporation of Application-November 9, 1950,Serial.No;196134;;

13 Claims. (01. 74 2o1)' The present invention relates to mechanism fordriving the elongate, flexible, magnetizable rec,- 0rd bodies used inmagneticv recording. and/oi" reproducing instruments, for driving therecord body past the magnetic head of the instrument. One aspect of theinvention relates to mechanism that comprises a motor, a mounting forthe motor and a mechanicalsystem for transmitting driving power from themotor to. a rotatable,

record body-driving. element, all arranged" in novel manner to prevent.disadvantageous effects: upon recording or reproducing qualityv oi theinstrument arising." from characteristics of magnetic, recording and/orreproducing instruments, the characteristics offelongate fieizible'record bodies, and the mechanical characteristics of constant speedmotors used. in such instruments for record body-driving purposes. Theprincipal problems arising, from these character istics of constantspeed motors used'insuch' inv struments for record body-drivingpurposes; The

principal problems arising from these characteristics are acousticpickup by the electronic am plifier system or motor" vibration,an'dfi'utter or the record'body as it passes the recording off-pick uphead imparted to it by vibrationof the motor and the elements ot-drlvetrain from-theinoto-r to the record 'body-driving-element, orfi'uttervariation in the speeds of the motorshaftanrt transmissionelements; e

To rotate a record body=driving spindle-that is stabilized by aflywheel-rotating 'withit it-has been proposed to drive the spindle andflywheel from the peripheryof the latter. To aecompl ishthis drive theperiphery of theflywheeliasur rounded by a resilient tire and the tireperiphery is frictionally driven'troman electric motor out put spindle.The tire; which is ofsome resiliel i't material as rubber orasynthetic-material haw ing friction and resilience characteristics reseni bling those ora -rubber, perfcrmsthe triple-functions of providing afriction surface for driven contact with the motor spindle-, a resilientbody for absorbing lateral vibrations'of theimotcr and an element of amechanical filter ofowhicha the flywheel provides a second element, themass of the flywheel being directly opposed. totransmission to thereoord-drivingspindle by the tire of minor flutter variations in themotor-spindle speed. To insure frictional contact betweertthe motorspindle and .tire adequate to drive the latter, the spindle lsspringbiased against the tire periphery, the motor being ,piv'otally1supported for swing of its spindle relative to the tire; The pressureexerted on the 'tir'e' periphery by the motor spindle during extendedidleperiodsof instrument tends to form a transverse-r-grocve across theflywheet periphery, whichuportsirbsequent operation, results in a-highlyobjectionable thumpat eaohfiywheeLrotation. 1 A second aspectof. theinvention relatestomechanis nfor removing'the spring-loiased motorspindle from, contact with the flywheeltire at eachstopping actuation ofthe motor switch. This is accent pushed by an atin link that is moy dibithe switch operator in moving from anontc on off position, to swinglthe.motor spindle away from the flywheel tire, but that is ineftectivetointerfere with the normal. biasing'ofthe; motor spindle against the tireso long as the motor switch operator isin its onposition.

Motor-control switches conventionally have detent means thattend tomaintain ,the movable switch element in an on or oiiposition to whichflitv has been moved. Such conventional, switch. detent meanshave been.found tobe capable, of maintainingthe motor, of ,a drive? mechanismarranged in accordance. with this invention. with its drive spindle. outof contactwith the flywheel tire, so long as the instrument isstationary, a dead center arrangement also maybe used to preventexertion; of the biasing, springforce (ii-.- rectly against the switchbiasingQmechanisin Shocks and sudden movements. as encountered intransportation, frequently are suflicient .to" release the actuatinglink from its dead center condition, and toovercome the switch detent,so"

that an, idle period following transportationjof an instrument mayresult in production at a grooved flywheel tire; An additionaliasp'ectof the invention relates: to a device, herein dis closed asusedin conjunction witfi the switch operator-controlled actuating link, but"having its own manual -actuator and therefore being independentlyuseiuhfor swinging the power assembly to a position wherein :themotorspindle is. spaced from'the flywheel tire, and; positively maintaining.the power assembly in that position until the actuator is moved to:release it.

AJprimary obiect'is' the provisionqof a novel} arrangement for mounting.a motor in a ma netic recording and/or reproducing instrument thatincludes meansjor absorbing, motor; vibration to preventitstrans'mission to the, remainder of the instrument and particularly tothe'electronic system thereof. Another object of the invention is theproyi= sion of a novel, unitary sub-assembly for mounting in a magneticrecording and/or reproducinginstrument, such assembly includinga1l=mecha nism necessary for drive and takeup of a magnetic record body.

An additional object is the provision of a novel vibration-absorbingmotor mounting prcto swing the motor to remove its spindle from contactwith the tire each time a motor switch is turned ofi, and to release themotor to establish the driving contact each time the switch is turnedon.

A further object is to provide a novel lock device for positivelysecuring a motor that is pivotally mounted and biased to maintain itsoutput spindle in driving contact with such a flywheel tire, in aposition wherein the motor spindle is spaced from the tire.

In the accompanying drawings:

Fig. 1 is a fragmentary vertical section of 'a magnetic instrument,showing in elevation a record body-driving and takeup assembly arrangedin accordance with the invention.

Fig. 2 is a transverse section on line 2-2 of Fig. 3 is a section online 3-3 of Fig. 1 showing the top plan of the assembly.

Fig. 4 is a longitulinal vertical section on line .4-4 of Fig. 3.

Fig. 5 is a horizontal section on line 55' of Fi 1.

I Fig. 6 is a horizontal section on line 6-6 of Fig. 1. V

Fig. 7 is a horizontal section on line 1'| of Fi 1.

Fig. 8 is a detail section on line 88 of Fig. 2, showing the pivot motormounting fixture.

Fig. 9 is a detail sectional view on the plane of line ,99 of Fig. 7,showing a motor mounting fixture that permits swinging about the pivotfixture of Fig. 8.

Fig. 10 is a detail section, on line |0|0 of is maintained spaced fromit, and an independent and manually actuated lock for securing the motorin its non-driving position. i

Fig. 12 is a top plan oithe assembly of Fig. 10. Fig. 13 i a section online |3I3 of Fig. 12. Fig. 14' is a section on line |4|4 of Fig. 13,showing'the switch operator-actuated mechanism in the condition of theofi position of the switch operator, andthe manual lock in itsnon-effective condition. Fig. 15 is a view similar to Fig. 14 butshowing the manual lock in its efiective condition. Fig. 16 is a sectionon line |6--|B of Fig. 13, showing an indexing detent for the manuallock. Describing the drawings in detail, and first ture that includes acover plate I0, which 4 shown as horizontally disposed. The instrumentis provided with a rotatable record bodydriving element, shown as acapstan roller I that advances a record body, typically of tape form,that is pressed against its surface by a pinch roll |2. Pinch roll I2 iscarried by a bracket structure l3 that is pivotally mounted and biasedby a spring M to urge roll |2 against roller H with sufficient pressureto assure drive of a record body trained between them. A motor switch l5mounted on plate I0 is operated by a shaft Hi, which also acts throughlinkage I! to swing bracket structure I3 and pinch roll l2 between theadvanced position shown and a retracted position'withdrawn from rollerII to permit record threading. .Swinging of roll |2 between its ad--vanced and retracted positions is correlated with movement of switchshaft IE to motor on and ofi positions. The pinch roll bracket structureand actuating linkage H are disclosed and claimed in application forUnited States patent, Serial No. 194,915 filed November 9, 1950, byEdmund Barany and Melvin Sackter.

The assembly of the present invention includes an upper fiat plate 20that may be supported in suitable manner in underlying relation toinstrument cover plate ID. A U-shaped lower plate 2| has a first sideflange 22 secured to plate 2|) along an end edge of the latter and asecond side flange 23 secured to plate 20 between the end edges of thelatter, so that a portion of plate 20 projects beyond flange 23. Atakeup reel spindle assembly 24 is rotatably supported in a bearing 25mounted in this projecting part of plate 20. Plates 20, 2| together forma rigid main structure for the unit. r

The takeup assembly 24 includes a spindle 26 projecting above plate'20,and in the instrument projecting through a hole 21 in cover plate In. Apulley 28 is secured to spindle 26 below plate 20.

A pair of bearing retainers 29 are mounted respectively on plates 20, 2|and support, in 00+ axial relation a pair of bearings 29a and the ro-'-tatable capstan assembly including roller H is rotatably supported inthese bearings. The capstan assembly includes a flywheel 30 and a driverpulley 3|, which are located between plates 20, 2 pulley 3| being linedup with takeup pulley 28 for driving the latter through a belt 32.Flywheel 30, in addition to functioning conventionally as an inertiaspeed-stabilizing device for capstan roller I, acts as a, driven elementin a drive train from an electric motor 33 to capstan roller and takeupspindle assembly 24. For absorbing motor vibration and preventing itstransmission to roller H, as well as to provide a suitable frictionsurface, flywheel 30 is provided with a peripheral resilient tire 34 fordriven friction contact with a motor driven spindle 35'. Flywheel 30 mayextend through an opening in flange 22 and belt 32 may pass through anopening in flange 23.

Spindle 35 preferably is an extension of the, armature shaft of motor33, and the motor is suspended by a system providing both for biasedswinging to maintain spindle 35 in proper frictional driving contactwith flywheel tire 34, and forabsorption of motor vibration to preventits transmission to plates 20, 2| and to the main structure of theinstrument.

A motor-supporting plate 39 is suspended from. plate 2| by threefixtures 40, 4|, 42 thatrespectively are secured to plate 2| by means ofholes 43, 44, 45 in the latter. These holes are located in a generallytriangular relation about the axis.

of the capstan assembly and bearings 29 (see Wis Figs; anal-69 Motorspindle 35 projects: tram: be'lbwplate 39 througl'r openings 46: inplates 39- and 2|, in a location generally between holes- 43 and- 443'and to-the-oppositeside offlywheel 30 from hole-4'3; Therelativelocationsof hole '43- and motor spindle35-sui-t the location ofthe axis of fixture 40, supported. in: hole 43,. t'o use-as a pivot axisabout which: spindle 35 'isswingable for being biased into properfrictional-driving contact with flywheel tire 34.

fiach-oifi'the 'pivot fixture 4E and the .flxt'ures 41:} 42: comprisesa: spacer collar .flfthat: is: seourerttoplatell by abolt 48 thatisthreaded into' hole 43; 4-4 or 45, and: the. :lower end. of Icollar4-1 slidably contacts the upper surface: or. plate 39. Bolt 483 offixture: 4fl penetrates:anratchinground hole 49 inplate 39; forming'therewith a: pivot support-. The bolts 49 of fixtures, 42' penetrateclearanceopemngs. 50. plate 39.. Washerade= vices-5|: supportedv on theheads ofbolts 48 .af-

fordrsliding support to'..the':.under: surface-of plate 39' aboutah01e49and clearance openings 50.

Motor-p33 is: suspended from'iand below plate 39 by three bolts .53;that are'rigidly' secured-- in themotonstructure: and have their upperends. supportedeby" nutsp5'4. resting-son. the: upper. surfacesoflresilient; grommets. 55 that are engaged in openings in plate 39...Plate 2-1 hasopenings 53. that. provide; clearanceior parts of-the:bolt," nutand grommet assemblies, that project above plate 39;:-

Plate 21 has; struck out from it a downwardly proiecting tongue 51. thatextends into a. clearance cove 58: of; plate 39 (see Fig. ,7), and. isproperlylocated: to provide a fixedanchor for one end of. a-,spr ing,59that has its otherqend secured to plate39 at a point suitable-forbiasing the swingingmotorx assembly to urge .motor spindle 35 againstflywheel-tire 34 with; proper pressure. forfriction' drive of thecapstan-assembly.

The above-described arrangement provides a complete, self-containedrecord driving and takeup unitfor mounting ina magnetic. recordingand/or reproducing. instrument. The resilient grommets 55- supported byplate 39 andsuspending motor 33 prevent transmission of motor vibrationthrough plate 39, and the pivotal support of the latter from the rigidstructure carrying. the capstan assembly permits proper biasing,

of the spindle ofuthe resiliently. suspended motor into frictionaldriving. relation with flywheel tire 34; The drive of the. capstanassembly by direct contact of the motor. spindle with the peripheralsurface of. the flywheel provides atransmission that is simpleandinexpensive-as comparedto prior transmissions employing idler or .beltand pulley trains .to a, spindle provided with aflywheel. driven throughthe. spindle and. having. only the function of. inertia stabilization ofspindle speed. The interpositionubetween the flywheeland the motorspindle. of a resilient tire, as. flywheel tire 34, not. only providesfor adequate friction- .for drivirig,,but additionally providesa.resil'ient,,mechanical filtering connection that permits the flywheel"inertia to ,maintain' a constantspeed regardless of vibrations 'or'flutter'of the motor spindle. t

Fig. lo'shows in section the details of .a specialized form of assemblythat includes a grommet 55, for suspending motor 33 from its pivotedsupporting plate 39. From Fig. itwill'be seen thatthe motor supportingbolts 53 comprise elementsoi hangers that alsoinclude spacer tubessurrounding the bolts and bearing against top surfaces of the motor;nuts 6|" that are threaded on boits st above tubes 691170 'tlghtenvthemaagainst the: motor surfaces; and; washers 621 that provide surfacescontacting theunder sidesrofi grommets Washers 63 underlie nutsillandlprovide surfaces contacting the opposite surfacesor grommets-55development; or the resilient grommet: as'-: sembly forvibration-absorbing support of motor it was discovered thatcompression:v or: 4 the grommet between washers-e2 63 by" forcing thelatter toward: the former, impairs the vibration. absorbing-f. qualityof the: grommet. To prevent suchcompression; andthereby' insure thatcompression of the grommet material is only by the motor weight; so thatthe motor is: supported by sheanresistance of; the grommet materialitssclosest' possible approaclirto optimum vibra-a tion-ahsorbingcondition, spacer structures are arranged inside the grommets to providestorr surfaces that=limit approach of the grommetcontacting surfacesofwashers 63 to the gro'tn' met-contacting surfaces of washers 62-toadistance substantially equal. to thecorresponding dimension of thegrommets when they are: in-

uncompressed condition. Such a spacerstructure is'shown in Fig. 10- as.a spacer tube 64 surrounding bolt 63' in the grommet and providing? endsurfaces respectively butting against the: grommet-contactingsurfacesofwashers 6'2}. 632

Figs. 11 to l6 disclose switch operator actuated means for swinging themotor toa non-driving position, wherein motorspindle 35' is spaced fromflywheel the 34, when the motor switch is opened, and--releasing themotor when the switch" is turned on, for biasing of spindle. 35 into itsnormal pressure-exerting iricti'on driving contact with the tire. Switchoperator shaft- H3 is provided with an extension 65 that projects belowswitch l5 and carries secured to it an actuator flange 66'. Pivot-allyattached to flange 66 in eccentric relation to shaft extension 65 is oneend of an actuator link 61. Link 61 is supported solely bythe mountingof its pivoted end to flange 66', and atits free second end it carriesabu-ifer' element 68 that is disposed in clearance cove 58' of plate 39.The angular'po'sition of the'pivot connection of link 6''! to flangeGBis so related to the angular position of switch shaft l5 that in the onposition ofshaft [E the link occupies the retracted'position shown inFig. 13 and in full lines in Fig. 14, with element 68 spacedfrom theedgesurfaces of plate 39 that define cove58; With rotation of switchshaft l6 to its ofi position, link 6? moveselement- 68 into the apexofcove 58' and swings motor pl-ate'39 counterclock wiseto the dottedline position of Fig. 14, wherein motor spindle 35 is spaced from theperiphery of flywheel tire 34. Advantageously the radial spacing andangular position of the pivot axis between link 6-1 and flange 66 are sorelated "to the angular distance between, and the locating of" the offand on positions of switch shaft it that adead center condition occursbetween plate 39 link 61 and shaft extension 65 when the latter is in"itsoff position, as suggested by the dotted linerepresentation of'link61 in Fig. 14;

In addition to the switch operator-actuated means described above, Figs.11 to 16' disclose an" independent device for swingingthe power assemblyto a non-driving position, with -motor spindle 35' spaced from theperiphery of flywheel. tire 34, or for locking the power assembly wheninthat position against release and swinging by the. bias spring 59'.The. provision of such a look; ing device in an instrumentalso-providedwith the mechanism :above described is desirable to preventshocks or sudden movements, as encountered in transportation, fromovercoming the off position detent of switch l5 and dislodging the deadcenter condition of link 41, thereby permitting bias spring 59 to swingmotor spindle 35 into. pressure-exerting contact with flywheel tire 34.

The lock in questioncomprises a shaft 10 journalled in the lower mainassembly plate 2| and having a head H journalled in the upper plate andextended above it for projecting through a hole 12 in an instrumentcover plate, as Ill Head H carries a hand knob or key I3, which may bepivoted as indicated in Fig. 11 for folding*to an out-of-the-wayposition. Shaft 10 projects below the lower plate 2! and throughanopening 1,4 in motor support plate 39 that provides a follower edge15. Registered with edge 15 for cooperation therewith and disposed inopening 14 is an eccentric cam 76 which is secured to shaft Ill androtatable with it from the inactive position of Fig. 14, wherein cam 16is spaced from edge 15 to permit bias spring 59 to urge motor spindleagainst tire 34, to the active position of Figs. 13 and 15 wherein thecam, by contact with edge 15, maintains motor plate 39 in a swung outposition wherein spindle 35 is spaced from tire 34.

Cam 16 preferably is so angularly related to 1 shaft H3 and followeredge 75, and follower edge 15 is so angularly disposed relative to itspath of swing with motor plate 39 and the location of shaft 10, that adead center relation exists between edge 15, cam 16 and shaft 10 whenthe cam is in its active position.

To secure shaft H3 and cam 76 in active condition against shocks andsudden movements, but to permit ready release by manual, turning ofshaft 10 from its locking position, a detent system is provided that isof specialized form to present strong resistance to release by jarringor sudden movements, but readily overcome by torque applied to shaft H1.The movable detent element comprises a plate l'i penetrated by shaft '10and secured to it for corresponding rotation, as by meeting flats of theshaft and edge of the plate shown at 18 in Fig. 16. Plate H has a pairof angularly spaced projections 79 that cooperate with a pin 80 thatprojects from support plate 2| tQjlimlt opposite rotation of shaft i0and cam it torthe two positions shown in Figs. 14 and 15. Indexingprojection and recesses are carried by one and the other of plates 2 I,11. As shown, the projections are provided by rivets 3i secured in plate2| in diametric opposition relative to shaft 10 and having rounded heads82 projecting from the under side of plate 2|. A compression spring 83-bears oppositely on the upper surface of support plate 2| and the innersurface of shaft head II, urging detent plate ll toward the undersurface of support plate 2|. Detent plate '11 is provided with a hole 86that registers with the head 82 of one rivet 8| when the shaft and camassembly l0, i6 is in its inactive position, shown in Figs. 14 and 16,and a' pair of holes 85 one of which registers with each rivet head 82when the shaft and cam assembly is in its active position,

shown in Figs. 13 and 15. The walls of holes 84,

85 preferably are axially contoured to match the rivet heads assuggested by the dotted lines of Fig; 16 and by Fig. 13. Spring 83serves to maintain a secure engagement of the rivet head or heads inholes 84 or 85 with which they are registered, but manual rotation ofshaft 10 readily releasessuch engagement by ammin -actioii bear tweenthe rounded rivet heads and contoured hole walls. 1 r

From the foregoing description andexplanae tions, the principles andadvantages of the invention will be understood, and it will'be apparentthat many changes may be made from the specific arrangements disclosedwithin the scope of the in;- vention as defined by the claims.

Weclaim: T 'I 1. In a magnetic recording and/or reproducing instrumentthat comprise mechanism for driving an elongate flexible record bodyincluding a .rotatable element and an electric motor having an outputspindle, said mechanism being convertible. between record body-drivingand idle conditions,' a wheel that is rotatable to drive-said rotatablevelement and a resilient tire mounted about its periphery, means mountingsaidmotor with its output spindle parallel to the axis of rotation ofsaid wheel and for swinging about 'apivot axis. disposed parallel to andspaced from the axes of rotation of said wheel and spindle for movementof the latter toward and away from the peripheryof said tire, and springmeans biasing the'motor about saidpivot axi in a direction to urge saidspindle into pressure-exerting contact with said tire periphery; a shaftmanually rotatable between two preselected positions, means actuable bysaid shaft for converting said-mechanism between its record body-drivingand idle conditions by rotation of said shaft between its two saidpositions, and means coupled eccentrically with. said shaft and actuableby its rot-ation to said positions respectively to swing said motor to aposition wherein its spindle is spaced'from -said tire periphery whensaid shaft ismoved to its. position to convert said mechanism toits'idle condition and to release said motor for urging of its spindleagainst the tire by said biasing spring means when said shaft is rotatedto'its other said position. I t

2. In a magnetic recording and/or reproducing instrument that comprisesa rotatable element fordriving an elongate flexible record body, a pinchroll that is movable into and out of pressureexerting relation tosaidelement, a powerassembly including an electric motor havingfan outputspindle, a wheelthat is rotatable to drive said rotatable element and aresilient tire mounted about its periphery, mean mounting said motorwith its output spindle parallel to the axis of rotation of said wheelandfor swinging about a pivot axis disposed parallel to and spaced fromthe axes, of rotation of said wheel and spindle for movement of thelatter toward andaway from the periphery of said tire, and spring meansbiasing the motor about said pivot axis in a direction to urge saidspindle into pressureexerting contact with said tire periphery; a shaftlocated in spaced relation to and mounted parallel to said pivot axisfor manual rotation between 'two' preselected positions, means includinga mechanical connection between said pinch roll andshaft for moving theformer to and from its said pres: sure-exerting relation during movementotsaid shaft between its said positions, eccentric means secured to androtatable with said shaft and disposed for cooperation with said powerassembly. to swing said motor, by rotation of said shaft to its saidposition wherein. said pinch rollis re; moved from itssaidpre'ssure-exerting relation, to anon-driving position wherein itsspindle is spaced from said tire periphery and, by rotation :01, Sa dshaft to .its other :position, to release said motor :ior swingingbysaid biasing spring;

:3. In azmagnetic recording and/r01 reproducing instrument thatcomprises a rotatable element :for driving an elongate flexible record.body, an electric motor tor-rotating said elementand having an outputspindle, and a switch controlling larx saof rotation of said wheel andfor swinging about a pivot axis spaced .from and parallel to the axesof.rotationof-said spindle and wheel for movement of the former t w rd ad away from the periphery of said ;ti,1 e,spring means bia ing the motorabout-said pivot axis in a direction to -:,ur;ge said :spindle ,-into.messure-exerting contact -=W th1said tire p rip er an mean pn ra i y voonnected with said switchoperator. and a-ctuable by movement of thelatter to its motor-stopp position toswing the motor about said .pivotaxisv to a position wherein saidspindle is spaced from said tire(periphery, and by movement of said operator to ,its motor--.oper2 ttionposition to release said motor for swingingby saidspring bias .xneans tourgesaidspindle into pressure=exerting contact with said tire periphery.

4. In amagnetic recording rand/orreproducing instrument-that comprisesarotatableelement for driving ,an elongate ,ilexible record body, ,anelectric motor for driving said rotatable-element and having anoutput .spindle, and a switch controlling said motor and :having anoperator shaftrotatable between two predetermined positions respectively :effective tomaintain said motor stopped and in operation; a wheel-thatis rotat-vable to drive said rotatable element and a resilient tire mounted aboutits periphery, -a plate secured to said motor in transverse relation tothe axis of rotation of itsspindle, means supporting said plate with theaxis of rotation of said motorspindle parallel to the axis of rotationof said wheel and for swinging about a pivot axis spaced from the axesof rotation of .said wheel and motorspin-dle .for movementof the latterto- -ward and away from the periphery of said tire,

spring means biasing said plate aboutrsaid pivot axis to maintain themotor spindle in pressureexerting contact with ,said tire periphery,eccentric means mounted on said switch operator shaft, anda linkconnected to said eccentric i means and movable, by rotation-of saidswitch operator shaft from (its motonoperation to its motor=stonPedposition, .from a position out of contact with s d pl te to contactitandswin it aboutsa dp o a sto etrac edros onwh re said motor spindlespaced from said tire peoriphery.

.5, in a magnetic recording and/or reproducing instrument thatcomprisesarotatableelementior driving an elongate flexible record body,:anelectrio motor for driving saidrotatable element .and having anoutput spindle, ands switch controlling said motor and having anoperator shaft oca ed in spa ed re ation to sa d rotatab e el ment androtatable between two positions respectively effective to maintain saidmotor stopped and in "operation a wheel thatis rotatable -to drive saidrotatable element and 'a resili-ent tire :mounted -about its periphery,a plate secured to said motor in transverse relation to the axis of.rotation of itsspindle, means supportring said plate with the axis ofrotation of said motor spindle parallel to the axis of rotation of saidwheel and for swinging about a pivot axis spaced from and parallel tothe axes ,of rotation plate to contact and swingit about saidpivot axisto aretracted position wherein saidmotorspindle is spaced from-said tireperiphery,said pivot axis, switch operator shaft, eccentric means,plateand link. being relatively disposed to establish a dead centerrelation between said shaft, Ilinkl nd-plate when said shaft .is in itsmotor-stopped position.

6. In a-magnetic recording and/orreproduo' i instrument that comprises-arotatable element for driving .an elongate flexible record body, .and anelectric vmotor having an output sp ndle; a Wheel thatisrotatable to.drive said rotatable element and a resilient tire mounted aboutitsperiphery, a power assembly including .a motor having an outputspindleiand means .mounti said power assembly with saidmotorsnindledisposed parallel to the axis of rotationof said wheelandiforiswingingabout a pivotaxis parallel to and spaoed'jrom the axes of rotation.ofsaid wheeltand spindlefor movement of the latter toward and .f-romtheperiphery of said tire, van actuatormanually movablebetween twopositions, and a thrust member having a surface for contacting ,asurfaceof said power (assembly, said thrust member being movable bymovement of' said actuator betweenits said positions froma positionwherein said memr and a resilient tire mounted about .its peri hery,

a plate securedto said motor intransverse relation to the axis ofrotation of itsspindle, means supporting said plate with the .ax-is ofrotation of said wheel and forswinging abouta pivot axis spaced from andparallel to the taxes of rotation of said Wheel andmotorspindleformovement of the latter toward and away fromv the periphery of said tire,spring .meanstbiasingsaid laterabout said pivot axis to maintain the.motor spindle in pressure-exerting contact with said tire periphemanactuatorshaftmanually rotatable between two preselectedepositionsnandxa. cammotatable by rotation of said actuator shaftbetweensaidpreselected positions from a first position-spaced i on; aconta t surfa e of said. plate to a second position bearing againstsaidsurfaceiandkmaintaining said plate in a position wherein, said motorspindle is spaced from contact with said tire periphery.

'8. In a-magnetio recording and/or reproducing instrument that comprisesa rotatable element for -'driving an elongate flexible record body, and

lan electric motor having an output spindle; a fixed support plate, awheel supported by said plate and rotatable to drive said rotatableelement and a resilient tire mounted about its periphery,

a motor-supporting plate pivoted to said fixed Plate for swinging abouta pivot axis disposed parallel to and spaced from the axis of rotationof said wheel, means mounting said motor on said motor-supporting platewith its output spindle disposed parallel to said axis of wheel rotation,and for movement of said spindle toward and l away from the peripheryof said tire by swinging of the motor-supporting plate, spring means 1effective, between said plates to urge said motor spindle intopressure-exerting contact with the periphery ofsaid tire, an actuatorshaft supported I by said fixed plate for manual rotation between twoangularly spaced preselected positions, and a cam rotatable between twopredetermined positions by rotation of said actuator shaftbetween itssaid positions, said cam having an eccentric surface disposed forcooperation with an edge of said motor-supporting plate and contoured tobe spaced from said plate edge in one of said positionsof the cam and bycontact with said edge in the other said position of the cam to maintainsaid motor-supporting plate in a position wherein said motor-spindle isspaced from said tire periphery.

9. In a magnetic recording and/or reproducing instrument that comprisesa rotatable element for driving an elongate flexible record body, and anelectric motor having an output spindle; a fixed support plate, a wheelsupported by said plate and rotatable to drive said rotatable elementand a :resilient tire mounted about its periphery, a

motor-supporting plate pivoted to said fixed plate for swinging about apivot axis disposed parallel to and spaced from the axis of rotation ofsaid wheel, means mounting said motor on said motorsupporting plate withits output spindle disposed parallel to said axis of wheel rotation andfor movement of said spindle toward and away from ,the periphery of saidtire by swinging of ,the ,motor-supporting plate, spring means efiectivebetween said plates to urge said motor spindle into pressure-exertingcontact with the periphery of said tire, an actuator shaft supported bysaid lected shaft positions, said cam having an eccen tric surfacedisposed for cooperation with an edge of said motor-supporting plate andcontoured to be spaced from said plate edge in one of said positions ofthe cam andby contact with said edge in the other said position of thecam to maintain said motor-supporting plate in a position wherein saidmotor spindle is spaced from said tire periphery.

10. In a magnetic recording and/or reproducing instrument that comprisesa rotatable element for driving an elongate flexible record body, and anelectric motor having an output spindle, a fixed support plate, a wheelsupported by .said plate and rotatable to drive said rotatable elementand a resilient tire mounted about its periphery, a motor-supportingplate pivoted to said fixed plate for swinging about a pivot axisdisposed parallel to and spaced from the axis of rotation of said wheel,means mounting said motor on said motorsupporting plate with its outputspindle disposed parallel to said axis of wheel rotation and formovement of said spindle toward and away from the periphery of said tireby swinging of said motor-supporting plate, spring means effectivebetween said plates to urge said motor spindle into pressure-exertingcontact with said tire, an actuator shaft supported by said fixed platefor axial movement and for manual rotation, a stop and detent platecarried by said shaft in facing relation to a surface of said fixedplate and movable toward and away from said surface by axial movement ofsaid shaft, a spring biasing said shaft and the detent and stop plateaxially of the former and to urge the latter toward said plate surface,said fixed plate and said detent and stop plate having means providingstop surfaces relatively disposed to stop opposite rotation of the shaftin two preselected positions, said fixed plate and said detent andstopplate having cooperative detent elements that are engageable byaxial movement of said stop and detent plate toward said fixed platewhen the shaft is in its said positions and said detent elements havingcooperative cam surfaces for releasing their engagement as the shaft isturned from said positions, and a cam rotatable by said shaft betweentwo positions respectively determined by said shaft positions, said camhaving an eccentric surface disposed for cooperation with an edge ofsaid motor-supporting plate and contoured to be spaced from said plateedge in one of said cam positions and by contact with said edge in theother said position of the cam to maintain said motor-supporting platein a position wherein said motor spindle is spaced from said tireperiphery.

11. A record body-driving assembly for a magnetic recording and/orreproducing instrument, said assembly comprising a supporting structureincluding a pair of fixed spaced plates having facing inner surfaces andouter surfaces, rotatable means comprising in coaxial relation a spindleextended between and rotatably supported by both said plates, a recordbody-driving element projecting beyond the outer surface of a first ofsaid plates and a fly-wheel positioned between said plates, amotor-supporting plate facing the outer surface of the second said fixedplate and pivotally mounted to said second plate for swinging about apivot axis spaced from and disposed parallel to the axis of rotation ofsaid rotatable means, an electric motor having an output spindle andsecured to said motor-supporting plate with said output spindle disposedparallel to said axis of rotation, extended axially through holes insaid motor-supporting and second fixed plates into registration with theperiphery of said wheel, and for lateral movement toward and from saidperiphery by swinging of said motor-supporting plate, a resilient tiremounted about the periphery of said wheel, spring means eifectlvebetween said supporting structure and motorsupporting plate to bias saidmotor spindle into pressure-exerting contact with the periphery of saidtire, a manually rotatable actuator shaft extended between and rotatablysupported by said fixed plates and projecting beyond the outer surfaceof the first thereof, cooperative means carried respectively by saidshaft and said supporting structure for limiting opposite rotation ofsaid shaft to two angularly spaced preselected positions, detent devicesrespectively carried by said shaft and supporting structure andreleasably engageable in said preselected shaft positions to restrainrotation of said shaft, and a cam member secured to said shaft andhaving'a portion projecting into a hole in said motor-supporting plate,said member having an eccentirc surface lying in said hole forcooperation with an edge that defines it, said surface being contouredto be spaced from said edge in one of said shaft positions and bycontact with it in the other said position to maintain saidmotor-supporting plate in a position wherein said motor spindle isspaced from said tire periphery.

12. A record body-driving assembly according to claim 11, wherein saidactuator shaft is axially movable, a stop and detent plate is secured tosaid shaft between the outer surface of said second fixed plate and themotor-supporting plate, a spring is arranged to bias said shaft axiallyin a direction to urge the detent and stop plate toward said secondfixed plate, said rotation-limiting means comprise surfaces respectivelyprovided by said stop and detent plate and carried by said second fixedplate in relative disposition to contact each other in said preselectedshaft positions, and said cam device comprise respectively roundedprojections from one and matching recesses in the other of said secondfixed plate and said stop and detent plate, said recesses andprojections being relatively arranged for registration and engagement byaxial movement of said shaft when in its preselected positions.

13. In a magnetic recording and/or reproducing instrument that includesmechanism that is convertible between operating and idle conditions, acontroller for said mechanism that i movable between two positionswherein respectively it is fill effective to maintain said mechanism inits operating conditions, a record body-driving capstan assemblyincluding a flywheel having a resilient peripheral tire, a motor havingan output spindle and means pivotally supporting said motor with saidspindle parallel to theaxis of said flywheel and for lateral movement ofsaid spindle to and from contact with said tire, and spring meansbiasing said motor toward pressure-exerting contact of said spindleagainst said tire; a common actuator movable between two positions, andmeans linking said actuator with said mechanism controller and with saidmotor for simultaneously moving said actuator to its position wherein itis effective to maintain said mechanism in idle condition and swingingsaid motor to remove its spindle from contact with said flywheel tire,and for releasing said motor and moving said controller to its othersaid position during movement of said actuator to its other saidposition.

EDMUND BARANY. MELVIN SACKTER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,254,066 Gruber et al Aug. 26,1941 2,438,265 Metzner Mar. 23, 1948 2,490,667 Boyd, Jr Dec. 6, 1949FOREIGN PATENTS Number Country Date 665,144 France M Apr. 30, 1929

